Entries in Garmin 276C
(3)

Wow, it's already mid-August and I failed big time in documenting my efforts from much earlier in the year when I built the comms box for the KLX250S. I won't go into great detail on the construction steps in this posting, but following the mounting of the Pelican case to the rear rack, I

Completed wiring up the radio, intercom and power distribution inside the case

Completed connecting everything up wiring and wiring it to the bike

Was hugely disappointed about the amount of alternator noise on the radio's transmit and receive audio(!)

Here are some pictures showing the construction efforts that went into the comms box.

Autocom and Yaesu radio mounted

Underside wiring - What you don't see

Where the wires will come out

Looks pretty clean

NMO-style antenna mount

Modified commercial PTT switch for the radio

I'd previously tamed some alternator noise on the GS by adding a 20 Amp DC Line Noise Filter from PowerWerx, so I ordered one up for this application and tried it out. It DID tame the noise on the receive audio through the intercom, but it didn't help at all on the noise that impacted the clarity of my transmit audio. So, after a brief period of head-scratching, I decided that I was simply asking too much of the little KLX250S's electrical system. I decided to go "off the grid" and go to a solar-charged, battery-only electrical system for the comms box.

Out came the DC relay that I'd use to switch electrical goodies on and off with the bike's ignition. That in itself didn't free up enough room for a battery inside the Pelican case, so I created a bracket to secure the battery to the top of the case. The battery is a 12 Volt, 5.1 Amp-Hr. sealed unit purchased from Batteries Plus

An Instapark All Black 5 Watt Mono-Crystalline Solar Panel was ordered up from Amazon. After a protection diode (1N5817) was added to the panel, a pair of aluminum brackets were fabricated to mount the panel above the battery and to the top of the case.

Simple brackets holding the solar panel and battery

Wiring details - no place to hide!

Another view of the 5 Watt solar panel

The Garmin and Yaesu head unit up front!

With everything mounted securely and wired, I'm able to say that the "off-the-grid" solution works as expected, with no electrical interference from the KLX250S. I decent sun, the solar panel extends the use of the radio, GPS and intercom well past the typical day of riding. An auxiliary power connector makes it simple to plug in for an overnight boost charge, too.

One of the things I'd planned to do with the comms box project is locate the Yaesu FTM-10SR "head" unit on a RAM mount somewhere up front on the Renthal bars. The head unit provides the display and all controls for the transceiver body which will be located in the Pelican 1200.

A trip to the hardware store netted a stainless metric bolt and washers, along with a nylon bushing to take up the space inside the mounting hole on the RAM-B-272. This RAM product is described as an Aluminum Mini Motorcycle Mount Angled Base with 9mm Hole and 1 inch Ball. It's actually intended to be bolted to the bike somewhere, allowing a RAM socket "arm" to extend outward to an accessory like a GPS. In this case, I turned things around, using the 272 on the back of the head unit instead.

After the nylon bushing was sanded down to a proper length, the stainless split washer was used to tension the bolt, making for a really secure assembly.

I used a couple RAM 231 U-bolt style mounts up front on the Renthal bar, intending for my existing Garmin GPSmap 276C to be on the left and the Yaesu head unit on the right.

With the U-bolt mounts bolted in place, I test fit the Yaesu head unit and GPS holder as shown below.

Here's the RAM 231 mount and extension arm on the right

And the 231 mount on the left for the GPS

Here's the actual Yaesu FTM-10SR/R "head" unit

Once the comms box project has been completed, wiring from the back will connect the Yaesu head unit to the transceiver. Power to the GPS and audio from it will also be connected and a Push-to-Talk switch controlling the radio will also be part of the ensemble.

My aging GPS has recently been suffering from FAS (floppy antenna syndrome). That is, the BNC mounted external antenna needs a little Viagra to stand straight up and continue pointing to the sky like it should. Over time, the plastic that provides a little friction between the GPS case and the antenna itself tends to wear due to vibration, allowing things to get a little sloppy. You'll know if your GPS has this problem if the antenna falls over to the right and looks like the photo below.

I've seen this problem solved with a rubber band (you know who you are), but I had a better idea. I figured a properly sized O-ring placed over the business end of the BNC connector on the GPS itself would cause enough extra friction with antenna to keep things pointing north. The BNC connector on the GPS is shown below.

Off to the hardware store I went to get an O-ring that fit the approximately 5/16" diameter of the BNC connector above. I came up with this:

I slipped it over the BNC and tamped it down to the base as shown in this photo.

Thinking this would do the trick, I aligned the antenna and popped it back in place. My thinking wasn't right - never really is. The antenna was still as loose as when I started. OK, maybe two O-rings would do the trick if they're stacked on top of each other. After a convenient stop back at the hardware store later in the day (they love me), I procured yet another identical O-ring and immediate stacked it on the other. STILL no success. What?!?

It was then I realized that the antenna's connector slips inside the BNC on the GPS and not over it. It would take quite a few O-rings stacked to provide enough friction to get the job done. It was at this point that I fished the 2nd one back off the BNC and tried something different.

Take Two: I placed the O-ring loosely over the end of the antenna's connector and lined things back up to reattach the antenna to the GPS. As I pressed the antenna into place, the O-ring is forced up and onto the BNC in a manner that it doesn't align perfectly, but provides just enough resistance to make things a whole lot tighter. Success!!

No more floppy antenna! So, for 63 cents (just one O-ring if you try it), I managed a cheap, effective solution. Because I bought two, I ended up with a spare that I can fish off the BNC connector in case I ever wear this one out. Try it!